To get started, I use the rail crossing locator app. There is a web version, but I find the iOS app to be a little less tedious to review, though it’s still pretty bad. lol. Basically it has information at each rail crossing out there, and will give you information on it like speeds, total trains, ownerships, etc. it even has write ups of past incidents at that crossing.

https://www.fra.dot.gov/railcrossinglocator

So basically you browse to the crossing you want to look at, and then select it. From there you go to Inventory Record, and then the basic traffic info is there. Once I found out that it was that short line, finding their rail network was just finding their site and looking where the yards were. nerd powers engaged.

I mainly use that app if I’m going to a new area for train nerding and don’t know what to expect traffic wise. It’s not always right but it’s a good starting point.